Apparatus for manufacturing discharge lamps

ABSTRACT

A discharge lamp manufacturing apparatus, especially for the manufacture of discharge lamps, is provided with a rotating central valve comprising an annular rotatable plate and an annular stationary plate. The valve is mounted so that the stationary plate is arranged above the rotatable plate. A cooling water tank is arranged in the space centrally of said valve. A driving system for the rotational parts employs reduction mechanisms in which the revolution of a driving device, which drives two turntables in synchronism, is transferred through a pair of cam means to each of said turntables through successively engageable pin rollers mounted on said turntables, said turntables carrying a plurality of spaced chucks for holding glass tube blanks. Each cam means is engaged with its curved surface by one of said pin rollers at a time whereby the turntables move intermittently and in synchronism.

United States Patet [191 Yamamoto et al.

[ July 31, 1973 APPARATUS FOR MANUFACTURING DISCHARGE LAMPS [73]Assignee: New Nippon Electric Company, Ltd.,

Osaka, Japan [22] Filed: Sept. 8, 1971 [21] Appl. No.: 178,749

[30] Foreign Application Priority Data Sept. 28, 1970 Japan 45/4596485[52] US. Cl. 316/30 [51] Int. Cl. 1101; 9/38 [58] Field of Search316/30, 31; 198/19;

[56] References Cited UNlTED STATES PATENTS 1,999,808 4/1935 Goodman137/625.46 2,162,209 6/1939 Trutner 65/270 X 1,951,142 3/1934 Foulke137/625.46

10/1970 Pityo et al 74/567 X 10/1958 Natalis 74/84 X PrimaryExaminer-Richard J. l-lerbst Assistant Examiner-J. W. Davie Attorney-W.G. Fasse [57] ABSTRACT A discharge lamp manufacturing apparatus,especially for the manufacture of discharge lamps, is provided with arotating central valve comprising an annular rotatable plate and anannular stationary plate. The valve is mounted so that the stationaryplate is arranged above the rotatable plate. A cooling water tank isarranged in the space centrally of said valve. A driving system for therotational parts employs reduction mechanisms in which the revolution ofa driving device, which drives two turntables in synchronism, istransferred through a pair of cam means to each of said turntablesthrough successively engageable pin rollers mounted on said turntables,said turntables carrying a plurality of spaced chucks for holding glasstube blanks. Each cam means is engaged with its curved surface by one ofsaid pin rollers at a time whereby the turntables move intermittentlyand in synchronism.

PATENTEU JUL 3 1 I973 SHEET 1 OF 5 PAIENH JUL 31 I975 SHEET 2 OF 5 Pmmiw3. 749.468

SHEET 3 UP 5 PATENIED 1m 31 ms SHEEI t [If 5 FIG.4

PATENTED JUL 31 1973 3. 749.488

sum 5 or 5 APPARATUS FOR MANUFACTURING DISCHARGE LAMPS BACKGROUND OF THEINVENTION This invention relates to an apparatus for manufacturing ofdischarge lamps, and particularly to a glass tube bending and exhaustingmachine for manufacturing fluorescent discharge lamps, especiallycircular discharge lamps. The invention is directed to improvedarrangements for the turntable driving device, for the central valve,and for the cooling system.

Conventional exhausting machines for manufacturing discharge lampsusually employ a central valve having two separable plates. The upperplate is rotatably mounted together with a single turntable, and thelower plate is fixedly secured to a stationary base member. Each ofthese two plates of the central valve has a contact surface. Thesecontact surfaces contact each other and are provided with a plurality ofgrooves filled with oil to form a film which provides an airtightconnection between these contact surfaces, so as to constitute theexhaust conduit between a vacuum pump and each of the lamp heads on theturntable. However, there has been a problem in that some oil in thegrooves tends to migrate or leak toward an air hole connected to theexhaust pipe in the central valve.

In a conventional lamp bending and exhausting machine each initiallylinear glass tube blank is held on upper and lower chucking means fixedto a single turntable. All the tubes are advanced synchronously and inpredetermined intervals for performing the steps of softening, bending,and exhausting each glass tube to produce the circular lamps. The stepsof softening and bending a glass tube require heating means which isable to maintain the temperature at about 900C to 1,000C, and which isinstalled in the path of the blanks. The temperature of the centralvalve is thereby greatly increased by the heat from the heating meanswhereby the vaporization of the above mentioned oil which migratestoward the air hole is accelerated, and undesired residual gases resultin the exhaust line connected to the blanks. In addition, contaminatinggasses, such as carbon dioxide, are also generated within the blanks, sothat the degree of vacuum is decreased and the operating characteristicsof the finished lamps are deteriorated by the presence of such undesiredgases. The provision of cooling means employing air blowing ducts orwater piping has been proposed to cool the central valve, but suchcooling has been insufficient due to the existence of heated air aroundthe machine.

In other words, the space below the central valve of the conventionalarrangement in which the stationary valve plate is installed, isnecessarily filled up with the piping of the exhaust line or conduits,and with the water, air, or gas pipes required for the cooling orheating means. The central portion of the machine is thus so complicatedthat when the central valve must be repaired or overhauled, variouspipes of the piping in and around the central valve must be lifted byusing a lifting device such as a chain block. Therefore, the disassemblyand reassembly of the pipes which fill the central portion of themachine is troublesome and requires much time so that the productivityis reduced by frequent repairs or overhauls.

On the other hand, the driving device for the turntable connected to therotatable plate of the central valve must maintain the accuratesynchoronous movement of both ends of each linear glass tube held on theturntable within exact intervals, in order to prevent damages to thetubes by deformation and twisting as a result of different phases in themotion of the upper and lower ends of the linear glass tube, which endsare held by said chucking means.

Since a pair of chucks each having arms of difi'erent length for holdingeach end of a linear blank, has been secured heretofore to a singleturntable, such deformation and twisting could not be removed completelyin previous machines. Thus, heretofore it was not possible to constructa drum turret type of turntable due to the location of the heating meansor oven in the path of the chucked blank. Therefore, the lower-sidechuck which holds the lower end of the linear blank had a relativelylong arm, and the lower portion of the linear blank could be easilyvibrated for a short time without momentarily stopping its vibratorymovement when the single turntable was stopped by the driving device.Thus, the linear glass blank is easily broken in the conventionalmachine.

In addition, the chucking means easily oxidized and eroded since itpassed through the heating oven, so that inspection and overhaul of thechucking means are required frequently in such prior art machines.Inspection and overhaul, as above noted, were very difficult.

OBJECTS OF THE INVENTION Accordingly, an object of this invention is toeliminate the disadvantages of prior machines and to provide an improvedbending-exhausting machine for manufacturing discharge lamps.Especially, the invention aims at solving the problem of arranging thecooperating elements of a discharge lamp manufacturing machine in such amanner relative to each other that an easy access is assured, whilesimultaneously maintaining the high sealing requirements necessary forestablishing a satisfactory vacuum, and holding the tubular blanks sorigidly that they cannot vibrate whereby to avoid breakage.

SUMMARY OF THE INVENTION According to the invention there is provided arotating valve, especially for a discharge lamp manufacturing apparatus,which has a stationary valve member arranged vertically above a rotatingvalve member so that the rotating member supports the stationary member.

The valve members are preferably annular toprovide a central easy accessspace, and in heat transfer contact with at least one of said valvemembers.

In accordance with an additional aspect of this invention, there isprovided an integrated driving system for a discharge lamp manufacturingapparatus, which system comprises a pair of annular turntables eachhaving a plurality of exhaust heads, chucks and pin-rollers spaced atequal intervals, a pair of cylindrical cams each engaging sequentially,one after the other, said pin-rollers, a pair of reduction mechanismsfor driving the respective cylindrical cam, and a driving device incommon for both cams to drive the turntables in synchronism and at apredetermined intermittent speed.

According to the invention, there are also provided means for indicatingthe amount of sealing fluid leaking from said central valve whereby tomonitor the operating efficiency of the central valve.

BRIEF DESCRIPTION OF THE FIGURES In order that the invention may beclearly understood, it will now be described, by way of example, withreference to the accompanying drawings, wherein:

FIG. 1 is a perspective elevation, partially in section, illustrating adischarge lamp manufacturing machine, especially a bending andexhausting machine embodying the present invention, in which thecomponents of the machine unnecessary for the understanding of theinvention have been omitted;

FIG. 2 is a partial longitudinal section through the bending-exhaustingmachine of FIG. 1 illustrating the machine in somewhat greater detail;

FIG. 3 is a cross section taken along the line III-III of FIG. 2;

FIG. 4 is an enlarged partial longitudinal section of the upper portionof the bending-exhausting machine of FIG. 2; and

FIG. 5 is a cross section taken along the line V-V of FIG. 4.

DESCRIPTION OFA PREFERRED EMBODIMENT FIGS. 1 and 2 illustrate theexhausting machine 1 secured to a base member 2. Only the maincomponents of the machine as related to the invention are shown. Themachine comprises three main supporting poles 3, only one of whichappears in FIG. 1 for simplicity, and an auxiliary pole 4 seen in FIG.2. The poles extend upwardly from the base 2 and each pole is dividedinto two parts for supporting the drive system. The supporting poles 3support a lower frame member 5 and an upper frame member 6, and theseframes support rotatable turntables 7, 8 respectively and a plurality offixed inside burners 9 of a heating oven 10, as shown in FIG. 1.

Preferably, the frame member 5 includes three annular stationary framesl1, l3, and (FIG. 2) fixed to an intermediate portion of the poles 3.The upper frame member 6 includes two stationary members 12 and 14 fixedto the upper end of the poles 3. Lower and upper pin wheels l7, 18respectively are mounted on the under sides of the turntables 7, 8 asshown in FIG. 2 and form a part of the turntables. Cross-roller bearings19, 20 are arranged between the pin wheels 17, 18 and the annular frames11, l2, 13, 14, respectively for rotating the turntables 7, 8. Aplurality of equally spaced lower pin-rollers 21 are mounted under theperiphery of the pin wheel. 17. Similarly, a plurality of upperpin-rollers 22 are mounted on the pin wheel 18.

The lower turntable 7 which forms an integral structure with the pinwheel 17 has a plurality of radially extending arms 23 at the peripherythereof, only one arm 23 is shown in FIG. 1. The upper turntable 8 whichforms an integral structure with the pin wheel 18 has a plurality ofarms 24 radially extending at the periphery thereof, only one arm 24 isshown in FIG. 1.

A linear blank 25 of a glass tube indicated by dashed lines is held bychucking means attached to each of the arms 23 and 24 and extendsbetween the arms 23 and 24. An upper chuck 28 at each arm 24 holds theupper end of the linear blank 25 so as to connect an exhausting tube ofthe blank 25 with an exhausting head 26 arranged on each of the arms 24.The lower end of each linear glass tube 25 is held by a separateadjustable support 27 which is attached to each of the arms 23 and heldby guide means 29 as shown in FIG. 1. The guide means may comprise, forexample, a roller positioned to ride on a fixed annular ring 29'. Whileonly one blank 25 is shown, a plurality of such blanks are actuallymounted on the turntables 7,8 for sequential processing in the machine.The components of the machine for bending the tubes do not form a partof the invention, and hence such components have been omitted to avoidconfusion in understanding the invention. Conventional components may beprovided for this purpose.

A pair of gear and cam reduction mechanisms 30, 31 which are arrangedbeneath each of the pin wheels 17, 18 of the turntables 7, 8, aremounted on the auxiliary pole 4 (FIG. 2) for reducing the revolution ofthe drive shaft driven by a drive motor 32 of a common fixed drivingdevice 33. Within a pair of gear boxes 34, 35 of the reductionmechanisms 30, 31, (FIG. 2) two rotating shafts 36, 37 and 38, 39respectively are arranged relatively crosswise for transferring therotary movement to the turntables. The rotating shafts 36, 37 areprovided with worm gears 40, 41, respectively and the rotating shafts38, 39 carry worm wheels 42, 43 coupled to the worm gears 40, 41 and tocam means of cylindrical cams 44,45.

FIG. 3 shows the components of the driving system for the lowerturntable. On the surface of the cylindrical cam member 44 there isformed a spiral groove 46 having a locus equal to the pitch spacingbetween two pin-rollers 21. Therefore, when the worm 40 engages the wormwheel 42 one after another of the pin rollers 21 of the pin wheel 17 isengaged with the groove 46 of the cylindrical cam 44 so as to provide anintermittent rotation to the lower annular turntable 7 by means of thepin wheel 17. The rotation of the rotating shaft 36 is transferred tothe rotating shaft 38 by the worm gear 40 and worm wheel 42, and furthertransferred by the pin wheel 17 to the turntable 7 by way of thecylindrical cam 44 and the pin rollers 21. The upper components of thedriving system have the same construction and perform the same functionas mentioned above whereby for each revolution of the cam member one ofthe pin rollers is engaged with the groove of the respective cam member.

Returning to FIGS. 1 and 2, the rotating shafts 36, 37 in the gear andcam reduction mechanisms 30, 31 are connected to each other by couplingmeans comprising a connecting rod 48 and a pair of bevel gear means 49.Therefore, rotation of both turntables can be effected by the commondriving device 33 which is connected to one of the rotating shafts 36,37. In other words,

when the driving device 33 is operated, the same rotation is achieved bytransferring rotation to both rotating shafts 36, 37 by way of theconnecting rod 48 and the pair of bevel gears 49.

A heating oven 10 with a plurality of gas burners 9 is arranged betweenupper and lower turntables. The linear blanks 25 are heated by the oven10 and softened for bending and exhausting the glass tube. As abovestated, only one tube is indicated by dashed lines. However, all tubesare heated in succession.

Referring now to the FIGS. 1 and 4, therein is shown the central valveportion in which a water tank 52 having an upper chamber 53 and a lowerchamber 54 is integrally installed at the center portion of the upperturntable 8. A rotary pressure joint 55 is attached to the upper chamber53 for filling cooling water into the top of the water tank 52. A rotarypressure joint 56 is attached to the lower chamber 54 for removing waterfrom the lower chamber 54. A plurality of holes 57 and 58 for watercirculation is formed in the side walls of each of the chambers 53 and54.

An annular central valve 60 comprised according to the invention of anupper stationary plate 61 and a lower rotatable plate 62 has a centerhollow within which the water tank 52 is positioned. The outer wall ofthe water tank 52 is directly connected to the rotatable plate 62. Thestationary plate 61 of the central valve 60 has a plurality of air holes63 spaced about its periphery. Only one air hole appears in FIG. 4. Therotatable plate 62 of the central valve 60 has a plurality of spaced airholes 64 (only one of which appears in FIG. 4) and grooves 65 on its topsurface. The air holes 64 are aligned with the air holes 64. The weightof the stationary plate 61 is substantially supported on the surface ofthe rotational plate 62, so as to provide an air-tight connectionbetween these two surfaces.

The grooves 65 are filled with lubricating oil to assure a tightconnection and to reduce frictional resistance caused by the rotationalmovement between the two plates 61 and 62 of the entral valve 60,thereby preventing sintering. Bearing means including needle bearings 66and thrust ball bearings 67 are located between the water tank 52 and anannular stationary frame 69 which is removably attached to an outerframe member 68 of the bending-exhausting machine as shown in FIG. 1. Asshown in FIG. 4, the stationary plate 61 is attached to the annularstationary frame 69 by connecting means such as bolts 71, and therotatable plate 62 is coupled to the water tank 52 by connecting meanssuch as bolts 70. A separate pipe 72 is connected to each of the airholes 63 in the stationary plate 61, and the exhaust line (not shown) isconnected to the pipes 72 (only one of which appears in FIG. 1). Theexhaust line also supplies filling gas for the glass tubes if desired. Aseparate air pipe 73 is connected to each of the air holes 64 of therotatable plate 62 of the central valve 60, and each air pipe 73 (onlyone of which is shown in FIG. 1) is connected as a separate exhaust head26 on the arms 24.

A separate transparent glass tube 74, only one of which is shown in FIG.1, is connected by way ofa separate pipe 75 to each air hole 64 for oilpooling so as to pool immigrated or leaked oil from the contact surfacesof the stationary plate 61 and the rotatable plate 62 of the centralvalve 60. As seen in FIG. 1, lubricant oil is supplied from an oiler 76suitably connected to the valve 60. The amount of oil leaked from thecentral valve 60 to the tube 74 indicates the operational conditions ofthe central valve 60 and the extent of the resistance in the exhaustline. This is an advantage of the present invention because the amountof leaked oil is visually apparent due to the use of the transparentglass tubes 74.

As shown in FIGS. 4 and 5, a separate water supplying pipe 80 isconnected to each of the holes 57 for water circulation in the upperchamber 53 of the water tank 52, and a separate water discharge pipe 82is connected to each of the holes 58 for water circulation in the lowerchamber 54 of the water tank 52. Branched pipes 84 and 86 of manifolds85 and 87 which are coupled to each of the water supplying pipes 80 andthe water discharge pipes 82, are mounted on the peripheral surface ofthe arms 24 of the turntable 8 (seen in FIG. 1) for cooling the exhaustheads 26. That is, cooling water furnished to the upper chamber 53 ofthe water tank 52 from the rotary pressure joint 55 flows into the lowerchamber 54 by passing through the water circulation holes 57, watersupplying pipes 80, manifolds 85, branched pipes 84 and 86, manifolds87, water discharge pipes 82, and water circulation holes 58, and isexhausted from the rotary pressure joint 56.

The circulation of cooling water through the pipes is thereforeeffective in cooling the central valve and the exhausting heads 26.Cooling of the rotatable plate 62 of the central valve 60 isparticularly effective, since the water tank 52 is directly connected tothe inner and botton walls of the central valve 60, and absorption ofheat energy of the rotatable plate 62 due to circulation of coolingwater is greater than that of the stationary plate 61 of the centralvalve 60. It is also possible to shield radiation from the heating oven10, by arrangement of the manifolds 85 and 87, water supplying pipe 80,water discharge pipe 82 and the like, so as to cool the zone around thetop of the turntable 8.

In the above mentioned construction, when the common driving device 33is connected to the lower reduction mechanism 30, rotation of therotating shaft 36 is transmitted to the rotating shaft 37 of the upperreduction mechanism 31 by way of the bevel gear means 49 so that bothrotating shafts 36, 37 can be rotated simultaneously at a high speed.Although some deviation of the speed between these two rotating shafts36, 37 is possible due to back-lash of the bevel gear means 49 or twistof the connecting rod 48 as the revolution speed varies, the differenceof speeds is significantly minimized at the rotating shafts 38, 39 dueto the reduction of speed of revolution by means of the reductionmechanisms 30, 31. The small difference in the speeds of the rotatingshafts 38, 39 is substantially removed by the reduced revolution speedof the pin wheels 17, 18 and the turntables 7, 8 due to the use ofcylindrical cams 44,45, so that the synchronized operation of the upperand lower arms 23,24 is achieved at the predetermined desired intervals.This is also a substantial advantage of the invention.

The upper turntable 8 is thus integrally rotated simultaneously with thewater tank 52 and the lower rotatable plate 62 of the central valve 60,and the complete air circulation path is intermittently formed throughthe air hole 64 of the rotatable plate 62, and the hole 63 of thestationary upper plate 61. Consequently, all the blanks 25 are exhaustedand filled with a desired gas necessary for completing the dischargelamps.

Since the water tank and piping of the present invention are arrangedabove the upper turntable, due to the location of the stationary plate61 above the rotatable plate 62, the structure of the machine issimplified. Which is also a great advantage of the invention. In otherwords, since according to the invention the water tank 52 and the pipingare eliminated from the space between the upper turntable and the lowerturntable, the necessary piping can be installed without affecting theinternal structure of the bending-exhausting machine so as to facilitaterepair and overhaul thereof.

Additionally, since the oil pipes connected to each of the air holes 64of the central valve are connected to the transparent tubes 74 for oilpooling, oil leaked from the contact surfaces of the stationary plate 61and rotatable plate 62 can be pooled within the transparent tubes 74.Accordingly, there is no residual oil near the air holes of the centralvalve, and there is no decrease in the degree of vacuum. It is also veryadvantageous that the amount of oil leaked can be visually observed dueto the transparency of the oil pooling tubes 74.

in another aspect of the invention, the cooling means for the machine iscomprised of the water tank disposed in the central hollow of thecentral valve having high heat conductivity, and by the water pipingextending to the exhaust heads, thereby forming a cooling zone in thespace surrounded by the central valve. Therefore, the central valve andexhaust heads can be efficiently cooled, and a decrease in the degree ofvacuum resulting from vaporization of oil present in the region adjacentthe air holes of the central valve can be completely prevented. Thereare no leaks of cooling water and no generation of water drops by aclosed circuit in the arrangement according to this invention. These arealso essential aspects of the present invention.

Further, since the driving system of the present invention comprises apair of turntables having a plurality of spaced chucks and heads, a pairof pin wheels having pin rollers, a pair of cam means having a cam locusshaped to engage one of the pin rollers at a time, and a common drivingmeans connected to each cam means through a pair of reduction mechanismsto rotate both turntables at the synchronous speed, the upper and lowerchucks attached to each periphery of the turntables are rotated with thesame phase between the upper and lower ends of the linear glass tubebefore bending. Therefore, damage of the linear glass tube is preventedby using the device according to the present invention.

In addition, it is possible to construct a large-size and high speedmachine for increasing productivity according to the invention. Sincethe construction is simplified and provides a large space between theupper and lower turntables, such large space can be utilized effectivelyfor maintenance, overhaul and repair of the machine.

Although the invention has been described with reference to a specificexample, it is to be understood that it is intended to cover allmodifications and equivalents within the scope of the appended claims.Thus, for example, the present teaching is not limited to circularfluorescent lamps, but is equally applicable to the manufacture oflongitudinal fluorescent lamps.

What' we claim is:

1. In an apparatus for manufacturing discharge lamps, having a centralrotating valve with a stationary valve member and a rotatable valvemember, the improvement comprising the arrangement of said stationaryvalve member vertically above said rotatable valve member and in contactwith the rotatable valve member, whereby the stationary valve member issupported by the rotatable valve member, said valve members having anangular shape to provide a central easy access space surrounded by saidvalve member, a cooling device for said rotating valve located insidesaid easy access space and in heat transfer contact with at least one ofsaid valve members, said cooling device comprising a water tank, meansfor rotatably supporting said water tank inside said easy access space,and means for mounting said rotating valve member on a portion of saidwater tank in heat transfer contact therewith. a turntable mounted forrotation with said water tank, and a plurality of discharge lamp holdingchucks carried by said turntable at the perimeter thereof.

2. The apparatus according to claim 1, wherein said water tank hasseparated upper and lower portions, comprising separate rotary conduitjoints connected to said upper and lower portions, and separate conduitmeans connected to couple said upper and lower portions to said chucks.

3. The apparatus according to claim 1, further comprising a secondturntable mounted below said first mentioned turntable, and drive meansfor said turntables comprising a plurality of pin rollers carried byeach turntable, a drive cam for each turntable having a curved camsurface located for sequential engagement with said pin rollers of therespective turntable for intermittent movement of the turntables, andmeans for rotating said drive cams in synchronism with each other.

4. The apparatus according to claim 3, wherein said means for rotatingsaid drive cams comprise respective reduction mechanisms, and means fordrivingly interconnecting the reduction mechanisms with each other 5. Anapparatus for the manufacture of discharge lamps, comprising a pluralityof poles secured to a base member, a pair of frame members mounted onsaid poles, a heating oven mounted between said frame members, a drivingdevice having a pair of reduction mechanisms mounted on one of saidpoles, said reduction mechanisms including cam means, a pair ofturntables having a plurality of exhaust heads and chucking means forholding glass tubes, said turntables being rotatably mounted on separateones of said frame members, a plurality of pin rollers connected to eachof said turntables and positioned to engage said cam means whereby eachof said turntables is intermittently ro tated by engagement between saidcam means and one after another of said pin rollers fixed to each ofsaid turntables, a central valve having a stationary plate part and arotatable plate part, said rotatable plate part being fixedly mounted onthe upper one of said turntables at a location below said stationaryplate part for supporting said stationary plate part, a water tankpositioned in the center portion of said central valve for cooling saidmachine, and an outer frame for preventing the rotation of saidstationary plate part of said central valve.

6. The apparatus of claim 5, further comprising a plurality oftransparent tubes fixed to said rotatable plate part of said centralvalve, each of said tubes being connected to pools of oil leaked fromthe central valve for indicating the amount of the leaked oil.

7. An apparatus for the manufacture of discharge lamps, comprising apair of vertically spaced apart fixed frames, a separate turntablerotatably mounted on each of said frames, said turntables including anupper and lower turntable, being arranged coaxially to each other, aplurality of pin rollers supported on each turntable, said pin rollersbeing equally spaced apart on each turntable and equally spaced from theaxis of rotation thereof, means on the periphery of said turntables forsupporting glass tubes therebetween, and means for synchronously drivingsaid turntables comprising a separate cam means for each of saidturntables and positioned to sequentially engage the pin rollers of therespective turntable, means for simultaneously driving said cam means, acentral valve having a rotatable member affixed to said upper turntable,and a stationary member above and supported on said rotatable member,whereby a seal is formed therebetween, a plurality of fluid ports insaid rotatable and stationary members for establishing intermittentfluid connections therebetween upon rotation of said turntables, saidrotatable and stationary members being annular, and further comprising awater tank mounted in the center portion of said rotatable annual memberfor rotation therewith, and rotary water inlet and outlet meansconnected to said tank.

8. The apparatus of claim 7, wherein said means for simultaneouslydriving comprises a separate reduction mechanism coupled to each cammeans, and means for 10 driving said reduction mechanisms in common.

9. The apparatus of claim 7, wherein said means for supporting saidglass tubes comprises exhausting pipe means, and means for connectingsaid water tank to said exhausting pipe means for cooling saidexhausting pipe means.

10. The apparatus of claim 7, comprising a plurality of air tubesconnected to said ports on said rotatable member, exhausting pipe meanson said upper turntable, and means connecting said air tubes to saidexhausting means for exhausting said glass tubes.

1. In an apparatus for manufacturing discharge lamps, having a centralrotating valve with a stationary valve member and a rotatable valvemember, the improvement comprising the arrangement of said stationaryvalve member vertically above said rotatable valve member and in contactwith the rotatable valve member, whereby the stationary valve member issupported by the rotatable valve member, said valve members having anangular shape to provide a central easy access space surrounded by saidvalve member, a cooling device for said rotating valve located insidesaid easy access space and in heat transfer contact with at least one ofsaid valve members, said cooling device comprising a water tank, meansfor rotatably supporting said water tank inside said easy access space,and means for mounting said rotating valve member on a portion of saidwater tank in heat transfer contact therewith, a turntable mounted forrotation with said water tank, and a plurality of discharge lamp holdingchucks carried by said turntable at the perimeter thereof.
 2. Theapparatus according to claim 1, wherein said water tank has separatedupper and lower portions, comprising separate rotary conduit jointsconnected to said upper and lower portions, and separate conduit meansconnected to couple said upper and lower portions to said chucks.
 3. Theapparatus according to claim 1, further comprising a second turntablemounted below said first mentioned turntable, and drive means for saidturntables comprising a plurality of pin rollers carried by eachturntable, a drive cam for each turntable having a curved cam surfacelocated for sequential engagement with said pin rollers of therespective turntable for intermittent movement of the turntables, andmeans for rotating said drive cams in synchronism with each other. 4.The apparatus according to claim 3, wherein said means for rotating saiddrive cams comprise respective reduction mechanisms, and means fordrivingly interconnecting the reduction mechanisms with each other
 5. Anapparatus for the manufacture of discharge lamps, comprising a pluralityof poles secured to a base member, a pair of frame members mounted onsaid poles, a heating oven mounted between said frame members, a drivingdevice having a pair of reduction mechanisms mounted on one of saidpoles, said reduction mechanisms including cam means, a pair ofturntables having a plurality of exhaust heads and chucking means forholding glass tubes, said turntables being rotatably mounted on separateones of said frame members, a plurality of pin rollers connected to eachof said turntables and positioned to engage said cam means whereby eachof said turntables is intermittently rotated by engagement between saidcam means and one after another of said pin rollers fixed to each ofsaid turntables, a central valve having a stationary plate part and arotatable plate part, said rotatable plate part being fixedly mounted onthe upper one of said turntables at a location below said stationaryplate part for supporting said stationary plate part, a water tankpositioned in the center portion of said central valve for cooling saidmachine, and an outer frame for preventing the rotation of saidstationary plate part of said central valve.
 6. The apparatus of claim5, further comprising a plurality of transparent tubes fixed to saidrotatable plate part of said central valve, each of said tubes beingconnected to pools of oil leaked from the central valve for indicatingthe amount of the leaked oil.
 7. An apparatus for the manufacture ofdischarge lamps, comprising a pair of vertically spaced apart fixedframes, a separate turntable rotatably mounted on each of said frames,said turntables including an upper and lower turntable, being arrangedcoaxially to each other, a plurality of pin rollers supported on eachturntable, said pin rollers being equally spaced apart on each turntableand equally spaced from the axis of rotation thereof, means on theperiphery of said turntables for supporting glass tubes therebetween,and means for synchronously driving said turntables comprising aseparate cam means for each of said turntables and positioned tosequentially engage the pin rollers of the respective turntable, meansfor simultaneously driving said cam means, a central valve having arotatable member affixed to said upper turntable, and a stationarymember above and supported on said rotatable member, whereby a seal isformed therebetween, a plurality of fluid ports in said rotatable andstationary members for establishing intermittent fluid connectionstherebetween upon rotation of said turntables, said rotatable andstationary members being annular, and further comprising a water tankmounted in the center portion of said rotatable annual member forrotation therewith, and rotary water inlet and outlet means connected tosaid tank.
 8. The apparatus of claim 7, wherein said means forsimultaneously driving comprises a separate reduction mechanism coupledto each cam means, and means for driving said reduction mechanisms incommon.
 9. The apparatus of claim 7, wherein said means for supportingsaid glass tubes comprises exhausting pipe means, and means forconnecting said water tank to said exhausting pipe means for coolingsaid exhausting pipe means.
 10. The apparatus of claim 7, comprising aplurality of air tubes connected to said ports on said rotatable member,exhausting pipe means on said upper turntable, and means connecting saidair tubes to said exhausting means for exhausting said glass tubes.